Rectifier assembly

ABSTRACT

673,375. Liquid - pressure engines ; hydraulic servomotor-control systems. HOBSON, Ltd., H. M., and WESTBURY, R. May 22, 1950 [June 2, 1949], No. 14844/49. Classes 69 (ii) and 135 [Also in Group XXVIII] A duplicated hydraulic power unit for operating the control surfaces of aircraft and other purposes comprises a pair of hydraulic servomotors directly coupled to a common output member 16, and means to short-circuit each servomotor in case of failure so that the other servomotor may continue to operate the output member, each servomotor having a supply pump 19 of the &#34;constant work&#34; type, i.e. one in which over its operating range its delivery pressure is substantially inversely proportional to its delivery and a control valve 42, the control valves being connected to a common input member 47, the operation of which causes corresponding movement of the output member 16. Fig. 2 shows a system similar to that shown in Fig. 2 of Specification 673,370 and comprising two jack pistons 10, 10a in tandem arranged in a moving cylinder block 13 connected to the output member 16. The jack cylinders 12, 12a are controlled respectively by valves 42, 42a, linked to the input member 47. The valves are supplied by separate pumps 19, 19a as described in Specification 582,182, [Group XXVIII], each comprising a gear stage 20 and a plunger stage having seven radial plungers 22 actuated by a cam 23 on the pump shaft 24. An off-loading valve 30 such as described in Specification 659,010 arranged in a line 35 between the stages is opened by a predetermined delivery pressure in the line 33 acting on a plunger 32. The pumps 19, 19a draw liquid from separate reservoirs 21, 21a and supply the control valves 42, 42a through inlets 38, 38a. Each inlet has a check valve 39 as described in Specification 673,370 which is closed positively on seizure of the corresponding control valve 42 by the collapse of a collapsable member 55 such as is described in Specification 673,369. At the same time a valve plunger 59 lifted by fluid pressure in the jack cylinder 12 opens a port 62 to connect the opposite ends of the cylinder independently of the control valve 42. Valves 74, 74a as described in Specifications 627,737 permit the circulation of fluid trapped in the jack cylinders when the pressure supply to both jacks fails and the cylinder block is moved manually by a nose 50 engaging stops 51. Figs. 3, 3a show a system similar to that shown in Fig. 5 of Specification 673,370 in which two hydraulic motors 17, 17a under the control of valves 42, 42a respectively drive through gearing 89, 89a, 90 a common output shaft 18 connected to screw jacks 93, 93a. The valves 42, 42a are connected to the input member 47 through a linkage 69, 71, 72, 72a, 73, 73a. Follow-up movement from the output shaft 18 is provided by a screwed rod 94 connected to the floating lever 69. Collapsable members 55, 55a as in Specification 673,369 are interlocked by plungers 97, 97a as described in Specification 673,372. The collapsable members 55, 55a control the closure of valves 82, 82a in the inlets 38, 38a and the opening of plunger valves 96, 96a short-circuiting the motor connections 87, 88. The pumps 19, 19a .each have a gear stage 20 which is driven from an electric motor and serves as a reduction gear in the drive to the plunger stage. Some of the plungers 22 of the latter stage are supplied through a conduit 68 and a passage 67 in the unloading valve 30 which shuts off the conduit 68 rendering some of the plungers inoperative when it opens. Each pump has a reservoir 21 and a charging valve 66. Figs. 4, 5, 11 12 show the construction of the hydraulic motors 17, 17a each of which comprises a cylinder block 99 with two banks of six radial cylinders 111, 112 containing pistons 78, 79 actuating eccentrics 76, 77 arranged in antiphase on shaft 75. The cylinders 111, 112 in each bank are aligned in pairs. The block 99 has end covers 100, 101, the former containing annular grooves 105, 106 connected by passage to unions 102, 103 respectively. Each pair of aligned cylinders 111, 112 is controlled by a piston valve 80 operated by a swash plate 182 on shaft 75 against a spring 81. Each valve has annular grooves 121, 124, 123, 126, the grooves 121, 123 being connected by a passage 122, and the grooves 124, 126 by a passage 125. Each valve 80 operates in a sleeve 107 arranged in a bore having two pairs of longitudinal grooves 108, 109, the grooves 108 being longer than the grooves 109. The grooves 108 are open to the annular groove 106 and the grooves 109 to the annular groove 105. The interior of the sleeve 107 is connected to the grooves 108 through ports 117, to the grooves 109 through ports 118, and through further ports to the cylinders 111. 112. Leakage into spaces 127 behind the valves collects in an annular groove 128 whence it passes through a spring-loaded valve 129 to an outlet 132. Specification 605,264 also is referred to. Reference has been directed by the Comptroller to Specification 617,375.

' July 28, 1959 K, s, BUTT 2,897,420

RECTIFIER ASSEMBIY Filed March 20, 195'? `10 mvo i 40 qe 23 l V Z5 9 Wm Ragni 15b 161 u B" pm United States Patent i RECTIFIER ASSEMBLY Kenneth Stanley Butt, London, England, assignor to Westinghouse Brake and Signal Company, Limited, London, England Application March 20, 1957, Serial No. 647,420

Claims priority, application Great' Britain March 29, .1956

9 Claims. (Cl. 317-234) The present invention relates to dry metal rectifier assemblies wherein one or more laminar metal rectifying elements lis or are juxtaposed with connectors, and such spacers, contact members and the like as may be required, to form a .column or stack.

It is one of the objects of the invention to evolve a form of construction, applicable particularly to small size assemblies, which enables the assembly to be made quickly and easily and consequently lends itself to production vby mass production methods.

According to the present invention, a stack including one or more laminar metal rectifying elements is held in position within a tubular case of electrically insulating material by connectors in the form of metal wires or narrow metal strips which pass through the walls of the case across the interior thereof and are constrained to lie externally of the case in grooves or recesses in the outer surface thereof. The grooves or recesses provide mechanical support for the portions of the connectors lying on the outer surface of the tubular case and thereby resist any tendency to disturb the electrical connec tions `of the connectors with the stack due to movement of the connectors Whilst connecting them to external circuits. The positioning of the stack by means of the connectors also reduces the number of components required in the assembly since means serving solely to tix the position of the stack are now no longer necessary.

The cross sectional shape of the tubular case is largely dependent on the outline of the rectifying elements in order that the elements may be a close-fit therein, and may therefore be, for example, circular or rectangular. If the connectors are of a ductile metal such as copper, the constraint maintaining them in their respective grooves or recesses may be inherent as a result of their being deformed by bending, but otherwise a sleeve or outer covering preferably fitted over the tubular case may supply the necessary constraint besides completing the electrical insulation of the assembly. Such a sleeve or outer covering is therefore of an electrically insulating material and although it conveniently takes the form of a length of tube which can be slipped over the tubular case, it may alternatively be formed directly on the case by winding thereabout a tape or thread composed of electrically insulating fibre or even by applying thereon a coating of some electrically insulating hard-setting compound.

Preferablyvthe tubular case is provided on the outer surface thereof with pairs of opposed grooves extending generally lengthwise of the case from one end thereof to the other and each of the connectors is associated with a different pair of the grooves, a blank end of the connector being bent down into the groove on one side of the case and the other live and being bent down into the other groove of the pair on the other side of the case and extending beyond one of the ends of the case in general alignment with the length lthereof for connection to an external circuit. In la circular section tubular case the grooves may extend obliquely over the external circular 2,897,420 Patented July 28, 1959 ice surface in the manner of a helix although manufacture is simplified if they extend longitudinally.

Thus, a long length of tubular insulating material may be preformed with the grooves and then be subdivided into the required lengths for use in the making of rectifier assemblies n accordance with the invention.

A method by which a dry surface contact rectier assembly is made consists, within the scope of the invention, in positioning a stack including one or more laminar metal rectifying elements within a tubular case of insulating material preformed with pairs of opposed grooves extending longitudinally in the external surface thereof and forming a hole in the wall of the case at transversely aligned points in the grooves of one of the pairs where one of the connectors is to enter into contact with the stack and likewise, forming holes in the wall at appropriate intervals along the length of the case where the other connector or connectors are to enter, choosing in each case different pairs of grooves, and passing metal wires or narrow metal strips acting `as connectors through the holes. Bending the ends of the wires or strips down into the grooves so as to leave, in respect of each such wire or strip, one of the ends projecting beyond one or other of the ends of the case for connection to an external circuit.

In describing the invention further reference will be made, by way of example, to one form of rectifier assembly constructed in accordance with the invention and illustrated in the accompanying drawings.

Fig. 1 is an elevation View, partially in cross section of an embodiment of the rectifier assembly in accordance with my invention;

Fig. 2. is a bottom view of Fig. 1;

Fig. 3 is an elevation view, partially in cross section, taken along lines III-III of Fig. 2,*and having the center portion removed;

Fig. 4 is a partial elevation view, partially in cross section, taken along lines IV-IV of Fig. 2; and

Fig. 5 is a perspective view of the tubular case and the wires of Fig. l.

Referring now to Fig. 1 the stack of rectifying elements is composed of two similar sections 9 and 10, each section having, in sequence, a spacer or contact member 11, a compression coil spring 12, two rectifier elements 13a, 13b in the form of plates coated with semi-conductive and counterelectrode layers .as indicated by the hatching, and a further spacer 14. The components of the stack all have a circuit outline of subtantially the same diameter and the stack is a close lit within a circular section tubular case indicated generally by the reference character 15.

The tubular case 1S is of insulating material and has pairs of diametrically opposed grooves designated16a 161C, respectively, extending longitudinally on the external surface of said case from one end to the other as best seen in Fig. 5. The length of the tubular case 15 1s longer than the assembled length of the stack to be accommodated therein, and for ease of manufacture is preferably cut from a greater length of tube stock which is preformed with the grooves 16. The tube may have the grooved shape imparted to it by extrusion through a suitable die as part of the process of formation or, subsequent to fromation, the grooves may Ibe cut as by milling. It is preferred to make the tube stock of any suitable hard synthetic resin.

The :grooves 16a-46)c are shaped to receive the full diameter of wire connectors 20, 21 and 22 which are used in the manner now to be described to position the stack within thetubular case. One of the connectors is to make connection with the spacers 14 of the two sections- 9 and 10 of the stack, the sections being inserted into the tubular case with the spacers 14 adjacent one another. .a The wall of thetu-bfular case is drilled at' 17a and 171i midway along the length of the case to form a' passageway which extends diametrically from groove 16a to groove 16b.

Selecting a different pair of grooves, say grooves 16b and 16e, the walls of the case are drilled at 18a and 18b at a point where the outermost face of one of the spacers 11 is located when the adjacent spring i2 is sufiiciently compressed. Likewise, the walls of the case are drilled at 19a and 1919 in the remaining grooves 16e and l6f and in the region of the other spacer 11. The connectors 20, 21 and 22 are tinned copper wire and are preformed in suitable lengths with a main portion, and another portion, of greater length than the outer diameter of the tubular case 15, perpendicular to the main longer portion. One of the connectors, designated 20, is then arranged with the perpendicular portion passing through the holes at 17a, 17h and between the spacers i4. The blank end of the connector, `being that amount of the perpendicular portion which protrudes externally of the case, is bent down to lie fiat in the groove 16d; the longer portion of or live end of the connector lies opposite thereto in groove 16a and is of sufdcient length to project Well beyond the end of the case toward which it is directed. The other two connectors 21 and 22 are inserted respectively through the pairs of holes i861, 18h and 19a, 19h with their live ends projecting beyond the other end of the case in order to distinguish`A them from the conductor 20; the ends of connectors 21 and 22 are bent down towards the middle of the case as shown in Figs. 3 and 4, respectively. While inserting the connectors 2l and 22, the spacers il are held down against their springs 12, the connectors being located to maintain in the springs a degree of compression corresponding to the contact pressure required in the stack.

The assembly is completed by fitting a sleeve 23 of insulating material over the tubfular case 15, the sleeve being of the saine length as the casesothat the live ends of the connectors protrude from beneath the sleeve at the ends of the case while the blank ends remain covered. The sleeve may be colord according to a code by which rectifier assemblies of differing characteristics may be recognized.

The construction in accordance with the. invention can be adapted to numerous alternative arrangements of the connectors relative to the stack components and also of the stack itself, since it is only necessary to ensure first of all that there is an adequate number of grooves in the tubular case to accommodate the number of connectors required and then to drill holes at appropriate points in the grooves. Where, for instance, a common connection is to be made at two separate locations inthe stack, a single wire connector may be made to execute two passes across the interior of the tube, one at each of those locations, and the blank end of the connector is'then brought back to lie in the same groove `as the live end of the connector. Instead of projecting from both ends of the case, as shown in the drawings, the connectors may, of course, project only from one or the other of the ends. As an example of an alternative form of stack which can be included in the assembly, there may be mentioned one in which a ball is included to act as a contact-electrode and so give to the rectifier assembly a high impedance characteristic.

The construction in accordance with the invention lends itself to incorporation in a sealed unit, in which the live ends of the connectors are all brought out at one end of the assembly which is housed wholly within a metal tube closed at one end, with the connectors projecting out of the other open end, the tube being sealed by afilling of a sealing material, for example, a synthetic resin such as an epoxy or polyester resin.

1. A dry metal rectifier assembly comprising a tubulai case of electrically insulating material, Said G35? includ- Having thus describedmy invention, what I claim.-

ing grooves in the outer surface thereof, connectors in the form of metal wires yor narrow metal strips arranged to pass through the walls of said case across the interior thereof, and a stack including at least one laminar metal rectifier element held in position within said tubular case by said connectors, said connectors having portions thereof constrained to lie in said grooves.

2. A dry metal rectifier assembly comprising a tubular case of electrically insulating material, said case including grooves in the outer surface thereof, connectors in the form of metal Wires or narrow metal strips arranged to pass throughthe walls of `said case across the interior thereof, a stack including at least one laminar metal rectifier element held in position Within said tubular case by said connectors, said connectors having portions thereof constrained to lie in said groove, and an outer covering of an electrically insulating material surrounding said tubular case and those portions of said connectors lying in said grooves.

3. A dry metal rectifier assembly comprising a tubular case of electrically insulating material, said case including grooves in the outer surface thereof, said grooves extending iri a direction generally lengthwise of the case, connectors in the form of metal wires or narrow metal strips arranged to pass through the walls of said case across the interior thereof, a stack including at least one laminar metal rectifier element held in predetermined position within said tubular case by said connectors, said connectors having portions thereof constrained to lie in said grooves, an outer covering of an electrically insulating material and in the form of a sleeve slipped over said tubular case and those portions of said connectors lying in said grooves, and respective ones of said connectors having portions protruding from beneath at least one of the ends of said sleeves.

4. A dry metal rectifier assembly comprising a tubular case of electrically insulating material, said case including pairs of opposed grooves in the outer surface thereof, said grooves extending generally lengthwise of the case from lone end to the other end thereof, connectors in the form of metal wires or narrow metal strips arranged to passe through the walls of said case across the interior thereof, a stack 'including at least one laminar metal rectifier element held in predetermined position within said tubular case by said connectors, each of said connectors associated with a dierent pair of grooves and having portions thereof constrained to lie in said grooves.

5. A dry metal rectifier assembly comprising a'tubular l case of electrically insulating material, said case including pairs -of opposed grooves in the outer surface thereof, said grooves extending generally lengthwise of the case from one end to the other end thereof, connectorsin the form of metal wires or narrow metalrstrips arranged to pass through the Walls of said case across the interior thereof, a stack including'at Yleast one laminar metal rectifier element held in predetermined position within said tubular case by said connectors, each of said connectors `associated with a Vdifferent pair of grooves andhaving portions thereof constrained to lieinrsaid grooves, and an outer covering of an electricallyinsulating material surrounding said tubular case and Athose portions of said connectors lying in said grooves. v

6 A dry metal rectifier assembly comprising a tubular case of electrically insulating material, said case including pairs of -opposed grooves in the outer surface thereof, said grooves extending generally lengthwise of .the case from one end to the other end thereof, connectors in the form of metal wires or narrow metal strips arranged to pass-through the walls of saidl case across the terior thereof, a stack including atleast one laminarl metal rectifier element held-inpredetermined position within said tubnlarcase by said connectors,'each of said connectors associated with a different pair of grooves andthaving portions thereof. 'constrainedtoglie in said grooves, the grooves of each pair being in diametrically opposed relation, one end of each of the connectors being bent down into a respective groove on said case and the other end of each of the connectors being bent down into said diametrieally opposed grooves of said pair, and at least one of the ends of said connectors extending beyond the ends of said case for connection to an external circuit.

7. A dry metal rectifier assembly comprising a tubular case of electrically insulating material, said case including pairs of opposed grooves in the outer surface thereof, said grooves extending generally lengthwise of the case from one end to the other end thereof, connectors in the form of metal wires or narrow metal strips arranged to pass through the walls of said case across the interior thereof, a stack including at least one laminar metal rectifier element held in predetermined position within said tubular case =by said connectors, each of said connectors associated with a different pair of grooves and having portions thereof constrained to lie in said grooves, the grooves of each pair being in diametrically opposed relation, one end of each of the connectors being bent down into a respective Agroove on said case and the other end of each of the connectors being bent down :into said diametrically opposed groove of said pair, at least one of the ends of said conectors extending beyond lche ends of said case for connection -to an external circuit, and an outer covering of an electrically insulating material and in the form of a sleeve slipped over said tubular case and those portions of said connectors lying in said grooves.

8. A dry metal rectifier assembly comprising a tubular case of electrically insulating material, said case including pairs of opposed grooves in the outer surface thereof, said grooves extending generally lengthwise of the case from one end to the other end thereof, connectors in the form of metal wires or narrow metal strips arranged to pass through the walls of said case across the interior thereof, a stack including at least one laminar metal rectier element held in predetermined position within said tubular case by said connectors, each of said connec tors associated with a different pair of grooves and having portions thereof constrained vto lie in said groove, the ends of said connectors projecting beyond the same end of said case in a direction generally lengthwise thereof for connection to an external circuit, a metal tube closed at one end housing said case, said connectors projecting out of the open end of said tube, and a lling of sealing material sealing said tube.

9. The method of manufacturing a dry metal rectiiier assembly having a tubular case of insulating material preformed with pairs of opposed grooves extending longitudinally in the external surface of said case, consisting of forming holes in the wall of said case at transversely aligned points in each of the pairs of grooves along the length of said case, said holes in each of said pairs of lgrooves being formed at predetermined spaced intervals with relation toA the holes in said other pairs of grooves, positioning a stack including at least one laminar metal rectifying element within said tubular case, passing metal wire connectors through said formed holes for supporting said stack, `bending down the ends of said wires into the respective grooves such that at least one end of each of said wires projects beyond one of the ends of said case for connecting to an external circuit.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No, 2,897,420 July 28, l959 Kenneth Stanley Butt It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line l, for "preformed" read @u performed Signed and sealed this 22nd dey of December 1959o (SEAL) Attest:

KARL H- AXLNE ROBERT C. WATSON Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 2,897,420 July 28, 1959 Kenneth Stanley Butt It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, lineA lo, for pre`ormed read e performed --0 Signed and sealed this 22nd day of December 1959e (SEAL) Attest:

KARL H MINE ROBERT C. WATSON Attesting Ocer Commissioner of Patents 

